Electrical distribution system



Dec. 18 1923.

L. C. WESCOAT ELECTRICAL DISTRIBUTION SYSTEM Filed Sept. 24', 192.1

Patented Dec. 18, 1923.

UNITED STATES PATENT OFFICE.

LEWIS C. WISCOAT, F CORONA, NEW YORK, ASSIGNOR TO WESTERN ELECTRIC CO]!-rm, INCORPORATED, OF NEW YORK, N. Y., A. CORPORATION OF NEW YORK.

EECTRICAL DISTRIBUTION SYSTEM.

Application filed September 24, 1921. Serial No. 502,984.

To all whom it may concern:

Be it known that I, Lnwrs C. WEscoAT, a citizen of the United States,residing at Corona, in the county of Queens, State of 6 New York, haveinvented certain new and useful Improvements in Electrical DistributionSystems, of which the following is a full, clear, concise, and exactdescription.

This invention relates to electrical distri- 10 bution systems, and hasparticular reference to a system which is adapted for ener ization fromeither of two sources, one o the sources being a normal source, and theother an emer ency source.

l5 It is t e primary object of the invention to provide a means forautomatically starting a' battery driven motor generator set whichserves as an emergency source when the normal source of current fails,and to close a circuit from the emergency source to the distributioncircuit when the emergency source is in full operation.

A further object is to provide a step-bystep load introducingarrangement. The

2 translating devices in the load circuit are divided into groups and acombination of relays in each group which may be termed' current limitrelays serve to close the circuit through each succeeding roup of 3translating devices when the trans ating devices in the preceding groupattain a state of full operation. In this manner too great a strain oneither current source is avoided.

More specifically the invention comprises an automatic two-sourcedistribution circuit which functions on an emergency source whenever itsnormal current source becomes inoperative. The failure of the normalsource serves to close, through the release of 40 the armatureofadeenergized' relay, the circuit of abattery-driven motor, whichactuates an emergency generator, the motor having two resistances inseries with its armature that function as starting resistances when themotor circuit is first closed. As the motor picks up speed and thecurrent through the circuit decreases, one of the two resistances isshort-circuited through the agency of a motor accelerating relay, and asthe current decreases further, the second resistance is short-circuitedby a second motor accelerating relay, and the battery current is leddirectly through the motor armature. The emergency source being in fulloperation, a circuit-closing device is operated to connect it to thedistribution circuit, and translating devices in this circuit aresuccessively energized as the emergency source furnishes suiiicientpower to take care of them.

The system illustrated in the drawing, which shows one embodiment of theinvention, is particularly designed to be used in cooperation withmachine switching panels used in automatic telephone exchanges of thetype disclosed in United States Patent N 0. 1,103,623 to J. N. Reynolds,dated July 14, 1914. In exchanges of this, type motors are employed toactuate the machine switching panels and with the use of the systemherein described, these motors are supplied from a commercial source,and, in case this source of current tails, are supplied with currentfrom a motor generator set driven by current supplied from a storagebattery located at the telephone exchange.

Although the present system is particularly adapted to operate inconjunction with an automatic telephone exchange of the t pe abovereferred to, it is to be understood t at the invention is not limited tothis application, but may be employed in conjunction with various typesof translating devicel where it is desired to operate them from eitherof two sources of current.

In the drawings, the elements of the system are shown in their normalositions in which current is being supplied the drive motorsn) which aredivided into oups, generally designated by letters G, t rough currentleads 1, 2 and 3, which constitute the normal current source.

In case the voltage impressed upon the leads 1, 2 and 3 fails, the drivemotors 9 will either be brought. to a dead stop or slackcnedconsiderably in speed according to their individual loads at the time ofthe current failure, and the group circuits of all but the first groupwill be interrupted.

Upon failure of the normal current source. a master control relay 28 isdecnergized.

which, through a group of relays generally smooth operation of theemergency source, the drive motors are cut into the circuit in groups.Sets of relays designated generally y the letter L, serve to connect thegroups of motors G to the emergency source, one group after another. Theentire system is thus energized step-by-step and continues to operate onthe emergency source, the total time taken for the transfer, assumingthat there are ten group circuits, being approximately ten seconds-fourseconds for starting t e emergency set and approximatel six seconds forthe introduction of the load: Upon resumption of the normal currentsource, the reverse transferring operation takes place through themedium of relays L. In this case, however, the emergency generator issto ped and the normal current source'is imm iately available.

As previously stated, the elements of the system are shown in thepositions that they occupy when the groups of motors 9 are beingsupplied by the normal'current source connected to leads 1, 2 and 3. Atthis time the master control relay 28 is energized over a circuit whichmay be traced from conductor 1, triple pole knife switch 4, knife switch29, conductor 30, windin of relay 28, conductor 26, switch 4 to conuctor 2. While relay 28 is energized its two armatures 31 and 32 areattracted and are held away from their contacts 33 and 34, respectively,interrupting the emergency system.

Upon failure of the current impressed upon leads 1, 2 and 3, relay 28will be deenergized, releasing its armatures. Armature 32 completes acircuit for a motor starting relay 57 of the group S, which may betraced from positive pole of battery 35, conductors 51, 64, 63, 62,winding of relay 57, conductor 61, armature 32 o relay 28, contact 34,conductors 60 and 36, to negative pole of battery 35. Relay 57 attractsits armature 69 and closes a circuit from battery 35 through startingresistances and 56, and throu h a direct current motor armature 14, whicmay be traced from positive pole of battery 35, conductors 51, 71,armature 69 of relay 57, conductors 68, 67, starting resistance 55conductor 70, starting resistance 56, conductor 66, armature 0 di rectcurrent motor 14, conductors 65, 36 to negative pole of batte The motor14 is of the shunt type, its fie d 74 being energized over a circuitextending from ositive pole of batte 35, conductors 51, 1, armature 69of may 57, conductors 68, 100, 72, a manually ad'ustable rheostat 73,shunt windin 74 con uctor 36, back to the negative po 0 of battery 35.

A motor' acceleratin relay 52 has two windings A and B. The winding A ofrelay 52 is in shunt of the terminals of armature 69 of relay 57 over acircuit from positive battery 85, conductors 51, 64, 63, winding A ofrelay 52, conductors 98, 99, 100, 67, resistance 55, conductor 70,resistance 56, conductor 66, motor 14, conductors 65, 36, to negativebattery. Vinding A will be short-circuited when relay 57 attracts itsarmature. Winding B of relay 52 is in shunt of starting resistance 55over the following circuit: positive pole of battery 35, conductors 51,71, armature 69 of rela 57, conductors 68, 100, 99, 101, winding ofrelay 52, conductors 102, 7 0, starting resiltance 56, conductor 66,motor 14, conductors 65, 36, to negative battery. Since the winding B isconnected across the terminals of resistance 55, it will be energized ba current having a potential equal to the drop across resistance 55which is sutficient during the first steps of the starting operation toenergize relay 52, causing it to hold its armature 49 out of engagementwith contact 48.

After the preliminary operation of relay 57, motor accelerating relay 52functions. It is normally sufiiciently energized, as stated above,through winding A, which is subject to a constant drain from thebattery, to hold its armature 49 out of engagement with contact 48,while the distributlon circuit is energized by the normal currentsource. Following the current failure and operation of relay 57 itsarmature 49 is closed a inst contact 48 as a result of theshort-circuiting of winding A by the operation of relay 57, and a dropin the potential of terminal points of resistance 55 and consequently ofwinding B as the starting inertia of motor 14 is overcome and thecurrent in the circuit is correspondingly decreased.

Contact closing relay 58 attracts its armature as a result of therelease of armature 49, the latter operation closing a circuit whichenergizes relay 58 from positive pole of battery 35, conductors 51, 64,50, armature 49, contact 48, conductor 113, winding of relay 58,conductor 61, armature 32 of relay 28, contact 34, conductors 60 and 36,to negative battery. Relay 58, in energizing, attracts its armature 75,which short-circuits the starting resistance 55 and energizes theemergency motor over a circuit which may be traced from positive pole ofbattery 35, conductors 51, 107, armature of relay 58, conductors 108,70, starting resistance 56, conductor 66, motor 14, conductors 65, 36back to negative battery. Resistance 55, being short-circuited, morecurrent willfflow through the motor 14 and its speed accordinglyincreased.

A second motor accelerating relay 53 has a winding C which is connectedin shunt of starting resistance 55 and is in parallel with winding B ofrelay 52. Its circuit may be traced from positive pole of battery 35,conductors 51, 71, armature 69 of relay 57, conductors 68, 100, 99,winding C of relay 53, conductors 103, 104, 102, 70, starting resistance56, conductor 66, armature 14, conductors 65, 36 to negative pole ofbattery. Winding C is energized by a current having a potential egual tothat of resistance 55 and of winding of relay 52. A second winding D ofrelay 53 is connected across starting resistance 56 in a circuit whichmay be traced from the positive pole of battery 35, conductors 51, 71,armature 69 of relay 57, conductors 68, 67, starting resistance 55,conductors 102, 104, 105, Winding D of relay 53, conductors 106, 66,motor 14, conductors 65, 36, to negative battery.

Upon the closing of the emergency drive motor circuit, motoraccelerating relay 53 is energized through its windings C and D over theabove circuits, and withdraws its armature 46 from engagement withcontact 45 during the first steps in the starting operation.Subsequently, after a short circuiting of resistance 55, and of windingC, and a decrease in potential of winding D, due to an increase in speedof drive motor 14, it releases its armature and closes a circuit throughthe third contact-closing relay 59 over a circuit from positive pole ofbattery 35, conductors 51, 64, 50, armature 49, contact 48, (at the timeof the operation of the contact of relay 53, relay 52 will bedeenergized) conductor 47, armature 46, contact 45, conductor 109,winding of relay 59, conductors 110, 61, armature 32 of relay 28,contact 34, conductors 60, 36, back to negative battery. Relay 59, inenergizing, draws up its armature 76 which closes a circuit from battery35, directly through the motor 14. This is the operating circuit for theemergency motor and extends from positive pole of battery 35, conductor111, armature 76 of relay 59, conductors 112, 66, armature of motor 14,conductors 65, 36 to negative pole of battery.

From the above it will be apparent that the motor accelerating relays 52and 53, the contact-closing relays S and resistances controlled therebyconstitute a rheostat auto matically controlled.

When the emergency motor generator set attains a state of fulloperation, the armatures of the two motor accelerating relays 52 and 53will have been released so that their contacts are closed and a circuitcompleted through their contacts and through triple contact relay 19,which may be traced from positive pole of battery 35, conductors 51, 64,50, armature 49, contact 48, conductor 47, armature 46. contact 45,conductors 44. 43, contact spring 42, contact 41, conductor 39, windingof relay 19. conductor 38, armature 31, contact 33, conductors 37, 36,to negative battery. Contact springs 24 and 42 are withdrawn fromcontacts 23 and 41, respectively, by the operation of relay 19.\Vithdrawal of contact spring 24 from contact 23 causes a break in thecircuit of relay 5, and prevents its energization, while the emergencyset is in operation. The withdrawal of contact spring 42 from contact 41puts a resistance 54 into the circuit of relay 19, which allows justenough current to flow through the coil of relay 19 to permit it to holdits armature in its closed position.

Relay 19, in energizing, completes a circuit from the emergencygenerator 13 through leads 15, 16. and 17, to the distribution leads 6,7. and 8. to actuate the groups of translating devices G. which havebecome inoperative as a result of the failure of the normal currentsource.

The translating devices 9, which are shown as comprising inductionmotors, are added to the distribution circuit, group by group, by meansof sets of relays L which are referred to in the specification andappended claims as current limit relays.

The first group of motors G is connected directly to the distributioncircuits 6, 7 and 8 through branch leads 76, 77 and 78 so that they willbe energized as soon as the relay 19 is energized. A relay 73 isenergized in series in one of the leads of the first group, so as to beresponsive to the current in said group, and is provided with a plunger79 which has a pin 80 perpendicular thereto, and which rests upon but isnot attached to a pivoted walking beam 81. Two other relays 74 and 75are energized in parallel across the leads of the distribution circuits6 and 7. Relay 75 has a plunger 82, which is pivotally connected to thewalking beam 81 and which has sufficient weight to normally hold theplunger 79 of the relay 73 in its elevated position. A contact arm 83,which controls the circuits of the relays 74 and 75, is pivoted at 84,and swings between a contact 87 and a stop 86. A weight 85. attached tothe contact arm 83, serves to normally hold the arm in engagement withstop 86, that is in its open position. A group contact closing relay 92is operated as a result of the joint action of the relays 73, 74, and75, and when operated, serves to close the energizing circuit of thesecond group of translating devices 9, through branch leads 76, 77, 78.

The operation of the current limit relays takes place in the followingmanner: The energization of the distribution circuits 6, 7 and 8 causesa simultaneous energization of relay 73 in series in one of the branchleads of the first group circuit, and relay 75. The circuit of relay 75may be traced from conductor 6, conductors 88, 89, winding of relay 75,conductors 90, 91, winding of relay 92, conductors 93, 94, to conductor7. The current flowing through relay 92 at this time is not sufficientto cause it to attract its armature 98. Plungers 82 and 79 of recal laysand 73, are held in their elevated positions, the latter plunger beingseparated at this time by a short space from the walkmg beam 81. As thetranslating devices 9 increase in speed, the current traversing thecircuit will correspondingly decrease, and relay 7 3 will becomeweakened, allowing its plunger 79 to fall against the walking beam 81,causing pin to engage contact arm 83 and to ull it into engagement withits corresponding contact 87. The operation of the contact arm 83 closesan energizing circuit for the relay 74 which may be traced fromconductors 6, 88, contact arm 83, contact 87, conductor 96 relay 74,conductor 97 to conductor 7. Ilelay 74 attracts its armature to whichthe weight is attached, and thus serves to lock contact arm 83 inengagement with contact 87. Simultaneously with this operation, relay 75is short circuited, its plunger 82 is released and allowed to fall,elevating plunger 79 of relay 73 and moving the pin 80 out of engagementwith contact arm 83, thus permitting free play of contact arm 83 for asubsequent failure of the current source and locating the plnngers forsubsequent starting operations. A second circuit is closed at this timethrough relay 92 which may be traced from conductors 6, 88, contact arm83, contact 87, conductors 95, 91, winding of relay 92, conductors 93,94, to opposite conductor 7. This energization of relay 92 is nowsufficient to actuate the armature 98 and the circuit to the secondgroup of translating devices is now closed through conductors 76 77 and78'.

Similar groups of relays are associated with each succeeding group oftranslating devices and operate in a manner similar to that justdescribed with reference to the first group. In this way a step-by-stepintroduction of the load into the distribution circuit is accomplished,and too great a strain on either the normal or emergency generator isavoided.

When the system is energized from its emergency source 13 and its normalsource again becomes effective, relay 28 is again energized, attractingits armatures 31 and 32, the former causing a deenergization of relay 19and the latter stopping the emergency motor generator. Relay 19, inreleasing its armature, closes through contact spring 24 an energizingcircuit for relay 5, which in attracting its armature, connects thenormal source to the distributing circuit, causing the successiveoperation of relays L to connect in the groups of translatin devices G.

at is claimed is:

1. In a system of electrical distribution, a plurality of translatingdevices, a source of current serving to normally supply said translatingdevices with energy, an emergency source of current normallyinoperative, means for putting said emergency source in operation whensaid first source fails, and further means serving to connect saidtranslating devices when said emergency source is in full operation.

2. In a system of electrical distribution, a plurality of translatingdevices, a source of current serving to normally supply said translatingdevices with energy, an emergency source of current comprising a motorgenerator system, means for setting said motor generator system inoperation when said first source fails, and further means serving toconnect said translating devices when said motor generator is in fulloperation.

3. An electrical power system comprising a main source of energy and anemergency source, said emergency source being normally inactive, meansfor automatically setting said emergency source in operation when saidnormal source fails, a load for said system and means for graduallyputting said load in circuit when the emergency source is in a state offull operation.

4. A system of electrical distribution comprising a normally activesource, and 2. normally inactive source of electrical energy, means forautomatically setting said inactive source in operation when said normalsource fails, a load and means for gradually placing said load in thecircuit of either of said sources.

5. In a system of electrical distribution, a distribution circuit, anormal source of current supply, and an emergency source both connectedto said distribution circuit, means for rendering said emergency sourceoperative when said normal source becomes inoperative, further means forrendering said emergency source inoperative when said normal source isoperative, and means for automatically connecting the load to either ofsaid sources as it becomes operative.

6. In an electrical power system, a source of supply normally serving toenergize groups of translating devices, an emergency source, means forautomatically setting said emergency source in operation when the normalsource fails, means for automatically stopping said emergency sourcewhen said normal current supp y is resumed, and means for introducingsaid translating devices into the distribution circuit step by step wheneither of said sources begins to energize its circuit.

7. A system of electrical distribution, a normal current source, anemergency source, a motor actuating said emergency source, a circuit forsaid motor, acce eratm relays, a resistance, means whereby said re ayswill out said resistance out of the motor circuit to automaticallyaccelerate the motor, groups of translating devices, means forsllocessively connecting groups of said translating devices to thecircuit when said circuit becomes energized, sa-id means comprising current limit relays in each group of translating evices whereby thecircuit to each succeeding group is automatically closed when' thedevices in full 0 eration.

8. n a system of electrical distribution, a normal current source and anemergency current source, groups of translating devices in thedistribution end of said system, group circuits for each group oftranslating devices, relays responsive to the current in each groupcircuit, means actuated by said relays for closing the circuit of eachsuccessive group of devices when the devices in the previous group arein operation.

In a system of electrical distribution, a normal current source and anemergency current source, automatic means for starting said emergencysource upon failure of said normal source, a series of translatingdevices energized in group circuits, and means for successively andautomatically energizing said group circuits.

10. In a system of electrical distribution, a normal current source andan emergency current source, groups of translating devices in thedistribution end of said system, group circuits for each of said groups,circuit closing devices for each circuit, and means for actuating thecircuit closing devices of each circuit as the translating devices inthe previous circuit are in operation.

11. In a system of electricaldistribution, a normal currentsource and anemergency current source, automatic means for starting said emergencysource upon failure of said normal source, a series of translatingdevices to be energized by said sources, and means for successively andautomatically energizing said series of translatin devices.

12. In a system of electrical distribution, a load divided into groupsand energized in branch circuits, a normal current source, an emergencycurrent source, actuating means for said emergency source, a storagebattery for energizing said actuating means, a circuit for saidactuating means, a resistance in said circuit, a relay responsive to afailure of the normal current source, serving toclose said circuit, arelay responsive to the current flowing through said resistance servingto short-circuit said resistance to start said actuating means.

13. In a distribution circuit, groups of translating devices, groupcircuits for said devices, means responsive to the current owing in oneof said group circuits for closing the succeedin group circuit, a normalsource of electrical energy serving to energize said distributioncircuit, an emergency source of energy, actuating means for the same,means comprising combinations of the previous group are under relayswhereby said actuating means'may be automatically started upon failureof the normal current source.

14. In a distribution circuit, translating devices, group circuits forenergizing said translating devices, means for automatically andsuccessively closing said group circuits, a source of electrical energynormally energizing said circuits, an emergency source of energynormally inactive, a motor for actuating said emergency source, abattery and means whereby a circuit through said motor will be energizedupon failure of said normal source.

15. In a system of electrical distribution, a supply' system comprisinga normal current source and an emergency current source, a loadcomprising a number of translating devices divided into groups, meansfor starting said load group by group, and means for setting saidstarting system in operation upon energization by the emergency currentsource.

16. In a system of electrical distribution, groups of translatingdevices, branch circuits for each group, means for automatically andsuccessively energizing said branch circuits, a normal source of currentfor said system, an emergency source of current normally inactive, meansfor actuating said emergency source, further means responsive to thecurrent from the normal current source for rendering said actuatingmeans inoperative during the operation of said normal source, an meanscomprising combinations of relays for automatically starting saidactuating means upon release of said current responsive means.

17. In a system of electrical distribution, a normal current source, anemergency current source, actuatin means for said emergency source,means or automatically starting said actuatin means when said normalsource is inoperative and stopping said actuating means when said normalsource is operative, groups of translating devices, branch circuits forsaid groups, alternately energized by said normal and emergency sources,means in each branch circuit re sponsive to the current in the precedingbranch circuit whereby said circuit is connected to the energizingsource when the current in the preceding circuit has decreased to apredetermined value.

18. In a system of electrical distribution, a normal current source, anemergency current source, means for actuating said emergency currentsource, means for automatically starting and stopping said actuatingmeans according as said normal current source is operative orinoperative, a load circuit comprising groups of translating devicesenergized in branch circuits, means situated in each circuit responsiveto the current flowing in said circuit for closing the following circuitwhen the current in said first circuit has reached a predeterminedminimum value, I

19. In a system of electrical distribution, a normal current source, anemergency current source, actuating means for said emergency source,means for startin and stopping said actuatin means, a loa circuit forsaid system comprising groups of translating devices energized in branchcircuits, means in each of said circuits responsive to a diminishincurrent in said circuit for connecting the following circuit to theenergizing source.

20. In a system of electrical distribution, groups of translatingdevices energized in branch circuits, a normal current source, anemergency current generator, actuating means for said emergencygenerator, an auxiliary current source, means responsive to a failure ofsaid normal current source for connecting said auxiliary current sourceto said actuating means when said normal 1921, source tails, resistancesin the circuit of said actuating means, and means responsive to thecurrent flowing 1n each of sand resistances serving to short clrcuitsaid resistances when the current in said resistances reaches apredetermined minimun value.

21. In a system of electrical distribution,

groups of translating devices energized in ranch circuits, a normalcurrent source, an

emergency current generator, actuating,

means for said emergency generator, an aux iliary current source, meansresponsive to a failure of said normal current source for connectingsaid auxiliary current source to said actuating means when said normal Isource falls, resistances in the clrcult of sand.

LEWIS c. wnsooa'r.

